[PATCH v3 6/6] aarch64: Add DLL import/export to AArch64 target

[Richard Sandiford]

Evgeny Karpov <Evgeny.Karpov@microsoft.com> writes:
> Monday, June 10, 2024 7:03 PM
> Richard Sandiford <richard.sandiford@arm.com> wrote:
>
>> Thanks for the update.  Parts 1-5 look good to me.  Some minor comments
>> below about part 6:
>> 
>> If the TARGET_DLLIMPORT_DECL_ATTRIBUTES condition can be dropped, the
>> series is OK from my POV with that change and with the changes above.
>> Please get sign-off from an x86 maintainer too though.
>
> Thank you for the review and suggestions. Here is the updated version of patch 6, based on the comments.
> The x86 and mingw maintainers have already approved the series.
>
> Regards,
> Evgeny 
>
>
>
> This patch reuses the MinGW implementation to enable DLL import/export
> functionality for the aarch64-w64-mingw32 target. It also modifies
> environment configurations for MinGW.
>
> gcc/ChangeLog:
>
> 	* config.gcc: Add winnt-dll.o, which contains the DLL
> 	import/export implementation.
> 	* config/aarch64/aarch64.cc (aarch64_legitimize_pe_coff_symbol):
> 	Add a conditional function that reuses the MinGW implementation
> 	for COFF and does nothing otherwise.
> 	(aarch64_expand_call): Add dllimport implementation.
> 	(aarch64_legitimize_address): Likewise.
> 	* config/aarch64/cygming.h (SYMBOL_FLAG_DLLIMPORT): Modify MinGW
> 	environment to support DLL import/export.
> 	(SYMBOL_FLAG_DLLEXPORT): Likewise.
> 	(SYMBOL_REF_DLLIMPORT_P): Likewise.
> 	(SYMBOL_FLAG_STUBVAR): Likewise.
> 	(SYMBOL_REF_STUBVAR_P): Likewise.
> 	(TARGET_VALID_DLLIMPORT_ATTRIBUTE_P): Likewise.
> 	(TARGET_ASM_FILE_END): Likewise.
> 	(SUB_TARGET_RECORD_STUB): Likewise.
> 	(GOT_ALIAS_SET): Likewise.
> 	(PE_COFF_EXTERN_DECL_SHOULD_BE_LEGITIMIZED): Likewise.
> 	(HAVE_64BIT_POINTERS): Likewise.

OK, thanks.  If you'd like commit access, please follow the instructions
on https://gcc.gnu.org/gitwrite.html , listing me as sponsor.

Richard.

> ---
>  gcc/config.gcc                |  4 +++-
>  gcc/config/aarch64/aarch64.cc | 26 ++++++++++++++++++++++++++
>  gcc/config/aarch64/cygming.h  | 26 ++++++++++++++++++++++++--
>  3 files changed, 53 insertions(+), 3 deletions(-)
>
> diff --git a/gcc/config.gcc b/gcc/config.gcc
> index d053b98efa8..331285b7b6d 100644
> --- a/gcc/config.gcc
> +++ b/gcc/config.gcc
> @@ -1276,10 +1276,12 @@ aarch64-*-mingw*)
>  	tm_file="${tm_file} mingw/mingw32.h"
>  	tm_file="${tm_file} mingw/mingw-stdint.h"
>  	tm_file="${tm_file} mingw/winnt.h"
> +	tm_file="${tm_file} mingw/winnt-dll.h"
>  	tmake_file="${tmake_file} aarch64/t-aarch64"
>  	target_gtfiles="$target_gtfiles \$(srcdir)/config/mingw/winnt.cc"
> +	target_gtfiles="$target_gtfiles \$(srcdir)/config/mingw/winnt-dll.cc"
>  	extra_options="${extra_options} mingw/cygming.opt mingw/mingw.opt"
> -	extra_objs="${extra_objs} winnt.o"
> +	extra_objs="${extra_objs} winnt.o winnt-dll.o"
>  	c_target_objs="${c_target_objs} msformat-c.o"
>  	d_target_objs="${d_target_objs} winnt-d.o"
>  	tmake_file="${tmake_file} mingw/t-cygming"
> diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
> index 3418e57218f..32e31e08449 100644
> --- a/gcc/config/aarch64/aarch64.cc
> +++ b/gcc/config/aarch64/aarch64.cc
> @@ -860,6 +860,10 @@ static const attribute_spec aarch64_gnu_attributes[] =
>    { "Advanced SIMD type", 1, 1, false, true,  false, true,  NULL, NULL },
>    { "SVE type",		  3, 3, false, true,  false, true,  NULL, NULL },
>    { "SVE sizeless type",  0, 0, false, true,  false, true,  NULL, NULL },
> +#if TARGET_DLLIMPORT_DECL_ATTRIBUTES
> +  { "dllimport", 0, 0, false, false, false, false, handle_dll_attribute, NULL },
> +  { "dllexport", 0, 0, false, false, false, false, handle_dll_attribute, NULL },
> +#endif
>  #ifdef SUBTARGET_ATTRIBUTE_TABLE
>    SUBTARGET_ATTRIBUTE_TABLE
>  #endif
> @@ -2865,6 +2869,15 @@ static void
>  aarch64_load_symref_appropriately (rtx dest, rtx imm,
>  				   enum aarch64_symbol_type type)
>  {
> +#if TARGET_PECOFF
> +  rtx tmp = legitimize_pe_coff_symbol (imm, true);
> +  if (tmp)
> +    {
> +      emit_insn (gen_rtx_SET (dest, tmp));
> +      return;
> +    }
> +#endif
> +
>    switch (type)
>      {
>      case SYMBOL_SMALL_ABSOLUTE:
> @@ -11233,6 +11246,13 @@ aarch64_expand_call (rtx result, rtx mem, rtx cookie, bool sibcall)
>  
>    gcc_assert (MEM_P (mem));
>    callee = XEXP (mem, 0);
> +
> +#if TARGET_PECOFF
> +  tmp = legitimize_pe_coff_symbol (callee, false);
> +  if (tmp)
> +    callee = tmp;
> +#endif
> +
>    mode = GET_MODE (callee);
>    gcc_assert (mode == Pmode);
>  
> @@ -12709,6 +12729,12 @@ aarch64_anchor_offset (HOST_WIDE_INT offset, HOST_WIDE_INT size,
>  static rtx
>  aarch64_legitimize_address (rtx x, rtx /* orig_x  */, machine_mode mode)
>  {
> +#if TARGET_PECOFF
> +  rtx tmp = legitimize_pe_coff_symbol (x, true);
> +  if (tmp)
> +    return tmp;
> +#endif
> +
>    /* Try to split X+CONST into Y=X+(CONST & ~mask), Y+(CONST&mask),
>       where mask is selected by alignment and size of the offset.
>       We try to pick as large a range for the offset as possible to
> diff --git a/gcc/config/aarch64/cygming.h b/gcc/config/aarch64/cygming.h
> index 76623153080..e26488735db 100644
> --- a/gcc/config/aarch64/cygming.h
> +++ b/gcc/config/aarch64/cygming.h
> @@ -28,12 +28,18 @@ along with GCC; see the file COPYING3.  If not see
>  
>  #define print_reg(rtx, code, file) (gcc_unreachable ())
>  
> -#define SYMBOL_FLAG_DLLIMPORT 0
> -#define SYMBOL_FLAG_DLLEXPORT 0
> +#define SYMBOL_FLAG_DLLIMPORT		(SYMBOL_FLAG_MACH_DEP << 0)
> +#define SYMBOL_REF_DLLIMPORT_P(X) \
> +	((SYMBOL_REF_FLAGS (X) & SYMBOL_FLAG_DLLIMPORT) != 0)
>  
> +#define SYMBOL_FLAG_DLLEXPORT		(SYMBOL_FLAG_MACH_DEP << 1)
>  #define SYMBOL_REF_DLLEXPORT_P(X) \
>  	((SYMBOL_REF_FLAGS (X) & SYMBOL_FLAG_DLLEXPORT) != 0)
>  
> +#define SYMBOL_FLAG_STUBVAR	(SYMBOL_FLAG_MACH_DEP << 2)
> +#define SYMBOL_REF_STUBVAR_P(X) \
> +	((SYMBOL_REF_FLAGS (X) & SYMBOL_FLAG_STUBVAR) != 0)
> +
>  /* Disable SEH and declare the required SEH-related macros that are
>  still needed for compilation.  */
>  #undef TARGET_SEH
> @@ -59,6 +65,12 @@ still needed for compilation.  */
>  #define TARGET_ASM_UNIQUE_SECTION mingw_pe_unique_section
>  #define TARGET_ENCODE_SECTION_INFO  mingw_pe_encode_section_info
>  
> +#define TARGET_VALID_DLLIMPORT_ATTRIBUTE_P mingw_pe_valid_dllimport_attribute_p
> +
> +/* Output function declarations at the end of the file.  */
> +#undef TARGET_ASM_FILE_END
> +#define TARGET_ASM_FILE_END mingw_pe_file_end
> +
>  /* Declare the type properly for any external libcall.  */
>  #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN) \
>    mingw_pe_declare_function_type (FILE, XSTR (FUN, 0), 1)
> @@ -158,6 +170,9 @@ still needed for compilation.  */
>    { "selectany", 0, 0, true, false, false, false, \
>      mingw_handle_selectany_attribute, NULL }
>  
> +#undef SUB_TARGET_RECORD_STUB
> +#define SUB_TARGET_RECORD_STUB mingw_pe_record_stub
> +
>  #define SUPPORTS_ONE_ONLY 1
>  
>  /* Define this to be nonzero if static stack checking is supported.  */
> @@ -168,4 +183,11 @@ still needed for compilation.  */
>  #undef MAX_OFILE_ALIGNMENT
>  #define MAX_OFILE_ALIGNMENT (8192 * 8)
>  
> +#undef GOT_ALIAS_SET
> +#define GOT_ALIAS_SET mingw_GOT_alias_set ()
> +
> +#define PE_COFF_EXTERN_DECL_SHOULD_BE_LEGITIMIZED 1
> +
> +#define HAVE_64BIT_POINTERS 1
> +
>  #endif